Doug Getgood lead the Toronto Survivalism Group on an excellent hike recently. Here are several things I learned:
Carry an epinephrine and Benadryl in case you have an unexpected reaction to a plant. Some can kill you quickly. Also to get an allergic reaction you often have to try the plant on two different occasions. [Notes from Wikipedia: "Benadryl is used as an antihistamine for the temporary relief of seasonal and perennial allergy symptoms. Benadryl is available for oral or topical use." From ehow.com's hiker's first aid kit page: "Benadryl can slow a moderate to severe allergic reaction, giving you more time to get someone to medical care." Also see Create a hiker's first aid kit. Regarding epinephrine, Shopwiki.com says: "If anyone in your family has life-threatening allergies, keep an epinephrine kit or an EpiPen in every first aid kit."]
Only pick a wild plant if there is an abundance. Only harvest up to 5%.
Avoid eating roots that come from soil that may be contaminated or near major roads. The greens are better as they absorb less toxins.
Avoid mushrooms as a survival food as they take more energy to find and collect than they supply in food value. They are very low in calories and fat.
Use field guide books to correctly identify plants and check if they are edible. Be very cautious. There are often similar plants that are poisonous or even deadly.
Doug uses Newcomb’s Wildflower Guide for identification. There is a index based on type of leaf and other characteristics. Next he uses Peterson Field Guide: Edible Wild Plants to check how edible the plant is. This book also shows poisonous look-a-likes.
Yarrow – “looks like the feather of an arrow.” Use for stopping bleeding. If you have a cold, a yarrow tea will warm the body.
Wild Mustard – edible but a bit harsh if you have too much. Eat seed pods or leaves.
Willow – you can eat the inner bark in an emergency. The bark has aspirin properties. Bendy branches can be used for weaving a basket.

